Nyal e. Nelson, 66, a civil engineer with the Army Corps of Engineers from 1946 until his retirement in 1980, died of cancer Oct. 24 at the Bethesda Naval Hospital.

Mr. Nelson, who lived in Herndon, was born in Waubay, S.D. He served in the Army in the Pacific in World War II and remained in the Reserves, retiring in 1976 as a lieutenant colonel.

He graduated from Washington State University in 1946 and then went to work for the Corps of Engineers. He worked in Seattle and Alaska before being transferred to Washington in 1964.

Mr. Nelson was a member of the Oakton (Va.) Ward of the Church of Jesus Christ of Latter-Day Saints. He also was a member of the American Society of Cost Engineers and the National Academy of Sciences.

Survivors include his wife, Vivien, of Herndon; three daughters, Stacy of Fort Lauderdale, Fla., Tally M. Johnson of Richmond, Va., and Kristi G. Anzivino of Amelia, Va.; a son, David of West Valley, Utah; two sisters, Myrtle Estes of San Diego, Calif., and Della Lucas of Eugene, Ore.; and five brothers, Howard, Byron and Clifford, all of Eugene, Ore., Harold of Thornton, Wash., and Melvin of Bridgeport, Wash., and eight grandchildren.